Most press brakes wear excessively across the surfaces of the ram and the bed though both proper and improper usage. A common and compromising corrective measure has been to place shims between adjacent tooling, and ram and/or bed surfaces, in an effort to improve the operative alignment of the tooling. This measure is generally unsatisfactory because the load is not transferred equally and proportionately from the tooling die set to the bed and ram of the press brake.
Additionally, excessive shimming causes longer set-up times and thus reduces productivity. In addition, the quality of the part being formed is diminished, often to the point of being unacceptable. The frequent result is that costly parts are scrapped.
U.S. Pat. No. 4,162,565 issued July 31, 1979 discloses a portable milling machine which can be transported to the location of a press brake needing reconditioning. This milling machine comprises an upper way, a lower way and a carriage. The upper way is attached to the upper moving ram member of the press brake and the lower way is attached to the lower fixed bed member of the press brake. Upper carriage support shoes travel along the upper way, and lower carriage support shoes travel along the lower way. Both sets of shoes are mounted on the carriage. While the carriage travels along the press brake, the cutter machines an edge of the press brake.
The installation of two ways, that is, upper and lower ways, requires that two sets of mounting holes be bored in the front faces of the bed and ram members of the press brake undergoing reconditioning. As a result, parallel alignment and the attitude of the two spaced way elements are quite critical often resulting in time consuming adjustments to correct errors in fastening the ways.
Additionally, the design of this prior art milling machine dictates that the movable carriage which supports the cutter be positioned relatively close to the front vertical surfaces of the bed and ram. As a result, this milling machine cannot be used to mill bed and ram surfaces and edges which are incorporated into bed and ram designs having wide, projecting shoulders. These shoulders obstruct the path of the carriage so that it cannot be mounted on the upper and lower ways.